Phonograph record



Aug. 30,1927. 1,64L42 A. A. JOHNSN PHONOGRAPH RECORD Filed Jan. 3, 1924 @all INVENTOR Patented Aug. 30, 1927.

UNITED 'STATES 1,641,142 PATENT oFFICE.

ANTH'UR A. JOHNSON, OF IBRDGEPOlT, CONNECTICUT, ASSIGNOR T0 DICTAPHONE CORPORATION, F IBBIDGQ'JPORT, CONNECTICUT, A CORPORATION 0F NEW YORK.

rHoNGBAPH nnconn.

l Application led January 3, 1924. Serial No. 684,166.

This invention -relates to soundrecords and in the embodiment herein illustrated it is' applied to sound-record tablets used in conjunction with dictating and allied machines. I

-Anobject of thisfinvention is to provide a record tablet having a suitable reinforcement to take-up some of the strain incidental to the operation of removing the tablet from l0 the machine and to contraction and expansion of the tablet due to temperature changes,

Another object is to provide a suitable form of reinforcement which will not inter-y Jfere with thelordinary processes of manu- !5 facture of sound-records, or require substantial changes of the form, size or composition of the records.

A further object is to provide a suitable reinforcement which will allow. the waxy material to flowthrough it and form a homogeneous mass through the reinforcement and at both sides of it, causing the reinforcement to be embedded i'n the surface ofthe record-tablet instead of merely lying 'upon its surface. And a still further object is to provide a cylindrical recordftablet having a helically fluted inside surface and having a cloth or other suitable reinforcement located at the bottoms Yof the flutes.

Other objects and advantages will hereinafter appear.

In the accompanymg. drawing: Figure 1 is a section of a cylindrical recl ord-tablet made in accordance with this invention.

Fig. 2 is a sectional view of the mold-.used in making the record-tablet, and showmg a cloth reinforcement located on` the core of the mold.

. inforcing element made in accordance with this invention.

v As shown in the accompanyingdrawmgs, the sound-recordtablet 10 is in the form of a hollow cylinder upon the periphery of which the'sound record is made by a suit- Fig. 3 is a perspective of one form of re' T he mandrel upon which the record-taba, let 1s placed is tapered, and, consequently, the 1nternal surfacewof the record corre-l spondmgly tapers from the small end 11 to the large end 12. The' taper is provided among other reasons, to enable the tablefto be easily withdrawn from the core when ybeing made and to allow the tablet tobe easily applied to and removed from the mandrel. In order to increase the grip of the mandrelupon the tablet, its inside surface is lluted, having helical ribs and groove .13. These ribs and grooves 13 are produced 1n the manufacture of the tablet by a iutedJ core 14 (see Fig. 2) mounted on a suitable 70 base l5 which also holds the shell 16 of the mold for shaping the record-tablet. The upper end of the shell 16 isopen andthe molten wax-like material is poured into the shell through this opening. After the Wa' material has suiiciently congealed, the she lp 16 is stripped from the record-tablet by suitable means, and then the core 14 is removed by rotating it while the tablet is held. In'thisoperation', the helical iutes ofthe 50 core act as screw-threads in ,facilitating the withdrawal of the core from the recordtablet and make it a very easy o eration.

After the record is remov from the core, and is seasoned, it is reamed to remove the top portions of the lands between the roots of the helical flutes as shown in-Fig.

1 so ,as to increase the contact surface of the record-tablet with the supporting mandrel l and to make it accurately fit the same. a0

From the above, it vwill be understood that it is extremely important to retain the helical ribs and grooves 13 on the inside surface of the tablet, and that any improvement 'or' change which necessitates the 95 abandonment of the ribs and grooves 13 will be ,accompanied by serious diadvantages. Consequently, in providing the reinforcel ment, an object of this invention is to provide for maln'ng a tablet so that both the 10o reinforcement and the helical ribs and lgrooves could be used. However, in attempting to do this, it was found-that ordinary cloth or other like material would be ressed against the core 14 so completely y the 105 molten waxy Vmaterial -that it would lie en tirely upon theinside surface of the tablet conformmg to the shape of the core by following the surface of the lands and flutesthroughout the vfull length of the core. Of uo cab To avoid these difficulties, this invention provides a stili', open-mesh textile fabric 17,

such as crinoline, for example. When thisl is well sized, it is found to be sufliciently stiff to resist the pressure of the molten waxy material and to permit it to flow through the cloth into the flutes of the core when the tablet is being molded. The cloth 17 being self-sustaining in any position, remains upon the lands of the core 14 and thus is disposed along the bottom or root of the helical groove near the inside surface of the molded tablet.

In practice, the cloth 17 is cut to shape and made in the form of a tapering tube, as shown in Fig. 3, so as to slip over the core to be held, by its own frictional engagement with the core, a short distance from both ends of the core. When the cloth reinforcement is made of sheet-material, its ends may be joined by a row of stitches 18. Or, the adjoining edges of the Cloth may be cemented together by a coating of silicate of soda (water-glass), ordinary glue, paraffin, egg or blood albumen, or other suitable binders or adhesives. It has been found that silicate of soda is probably the most satisfactory, considering the relative cost, for it is easily applied and holds well under all working temperatures of the waxy record materia After the lining or reinforcement 17 has been made it is slipped upon the core 14 as Shown in Fig. 2 and the molten waxy material of which the tablet is composed is poured into the mold in the usual manner. When the tablet cools, after having been stripped from the shell and core, as above described,

it can contract unrestrictedly and in roportion to its varying thicknesses at ifferent places along its length caused by the helical fluting and the taper. Consequentl there 1s no internal strain produced in tie cooling operation so long as the core is removed before the record material is allowed to set.

When the reinforced record tablet of this invention is reamed, only the tops of the lands of waxy material are removed but the cloth 17 is not reached b the cutter, because the cloth 17 is complete y embedded in the tablet 10 at the points corresponding to the ottom or root of the helical groove in the tablet. In a tablet made in accordance with this invention, there is a sufiicient quantity of material upon the inner side of the reinforcement to cause it to be securely united to the main body portion of the tablet; and, thus, chipping or scaling-oli of these parts is revented.

t should be clearly understood that this invention is not limited to the use of crinoline or like textile fabrics, but that other open-mesh material, such as wire-cloth or screening, or even expanded metal or perforated metal sheets may be used Within the scope of this invention, so long as the material is relatively stiff and allows the record material to pass through it.

Again, while there are certain decided advantages, above pointed out, in the use in combination of the reinforcement of stiff, open-mesh material and the helical fluting of the record, it should be understood that this invention is not limited to the use of such a reinforcement with that particular kind of record formation, but that the still' openmesh reinforcing element may advantageously be used, because of its self-sustaining qualities, with any desired record formation whether it be smooth or irregular on its surface adjacent which the reinforcement is to be located. f

Other variations and modifications may be made and ortions of the improvements may be used Without others within the scope of the appended claims.

Having now described the invention, what is claimed as new and for which it is desired to obtain Letters Patent, is:

1. A cylindrical sound-record tablet having a cent-ral bore provided with a helical groove, and having a reinforcing strip of open-mesh fibrous cloth embedded therein and located at the part of the tablet circumscribed by the root of said helical groove.

2. A cylindrical sound-record tablet having a tapering, tinted bore, and a sized fabric embedded therein adjacent the bottoms of the flutes.

3. A cylindrical sound-record tablet having a tapering bore and a reinforcin strip of sized fabric located adjacent the ore.

4. A molded cylindrical sound-record tablet having a tapering bore and having adjacentbut spaced from its inside surface a reinforcing strip of foraminous fabric, the foramina of the fabric being of such size as to permit molten record material to freely flow through them when the record is being molded.

5. A sound-record tablet having a strip pf reinforcing sized fabric embedded there- 1n.

6. A sound-record having a working surface. and a'supporting surface and a strip of stiff reinforcing fibrous cloth located between the working surface and the'supportin surface.

A molded sound record formed of a wax-like record material and having` an in- 5 ternally uted surface, the lands of the utes being flat to have substantial enga' ement with e record support. and a, rem orcing :foraminous cloth embedded in said record material and lyn adjacent the root of the 10 flute, said cloth belng still' and open mesh so as to withstand the pressure of the'molten record material a inst it without deforming, and permit t e molten record material to ow through the foremina of the cloth in- ARTHUR A. JOHNSON. 

